Telephone switch for radio sets



Jan. s 1926K. ,1,568,297k

E. A. SMALENBERGER TELEPHONE SWITCH FOR RADIO SETS Filed sept. 24, 1924A TTORNEYS Patented Jan. 5,

N uNiTED 'STATES PATENT OFFICE.

EDWARD ANTHONY SMALENBERGER, OF BROOKLYN, YORK, ASSIGNORFRANKLIN'L-DUERK. OF BROOKLYN, NEW YORK.

TELEPHONE SWITCH Fon RADIO s E'rs.

i Application led September 24, 1924. Serial No. 739,521.

To all w71 om. t may concer-n."

'Be it known that I, IJDwARD- ANTHONY SMALnxn'Enuicn, a citizen of theUnited States, residing at Brooklyn. in the county of Kings and. Stateof New York, have invented cei'tain new and useful Improvements linTelephone Switches for Radio Sets, of which the following is a full,clear, and exact description.

This invention relates lto switch ,devices for connecting a plurality ofcircuits in various relations to a common circuit. Such a -switchdevice, for example, has consid- Aerable utilityfor the telephonecircuits of radio sets.

In the customary operationo'f *radio sets, the tuning isusuallyaccomlplished` withhead telephones, and after a desired station has beenlproperly timed in, connection is made to a loud speaking receiver. Inview of the difference in -impedaiice between head sets and loudspeakquently desirable to connect auxiliary circuits in vai'iousrelations to acommon circuit sucli as for balancin the same and se-`lectively incapacitating either auxiliary circuit and it is 4,to suchvciriiits 4that (this invention particularly relates.

An object of this invention is to -provide an improved switching devicewhich will satisfactorilyl solve the diihculties `above mentioned andwith which itheauxiliary circuits may be connected in series lwith oneanother and to a common-circuit in such a 1mannerthat either auxiliarycircuit may be telephones and loud speaker maybe used simultaneouslywhile receiving eitherwealr or strong signals without discomfort orannoyance tothe operator; and with which .either the telephones or loudspeaker may be opeiated singly and selectively by simple manipulations.v

A. further object is to provide an 'improved switch for connectingeither the telephones, or loud speaker, or both, to the radio lreceiving set selectively, which may be incorporated in a teleph'oneplug. v

A further object is to provide animproved switch for accomplishing eachor all of the above objects .which will be relatively simple, compact,durable and relatively inexpensive. Other objects and ad-l vantages'will be apparent from'the following description of an embodiment of theinvention, and the novel features will be articularly pointed out in theappended claims.

The invention comprises 'various features' to which attention willbedirected in connection with the following description of theapplication of the invention to telephone switches of radiosets.

In .the accompanying drawing Fig. 1 is an elevation of a switchconstructedin accordancewith the invention, with the closurev wallremoved;`

llig. 2 is a longitudinal sectional elevation of the switch;

Fig. 3 is a transverse sectional elevation of the same, with thesectiontaken substantially along the line 3-8 of Fig. 1;

'F ig. 4 is atransverse sectional elevation of a slightly modifiedconstruction, with .the section taken along a line corresponding to thatfor Fig. 3; and

Fig. `5 is a diagrammatic illustration of the electrical connections,illustrating the use of the invention. i v

Referring especially to the particular embodiment of the invention whichis. illustrated in Figs. 1, 2, 3 and 5,' a base member 1 of suitableinsulating material, such as fibre, -hard rubberor phenol condensationproducts, isA provided with an `aperture 2, extending fromv face toface,in which a spindle 3 is rotatably mounted. This spindle .mayconveniently comprise a screw, having ahead 4, and an operating button 5threaded upon the other end, the button 5 having a closed cavity intowhich the screw is threaded so that when the screw strikes the bottom ofthe cavity, the button will be locked to the'sciew in auch a. mannerthat 11o -connections therewith at all times.

when the button is manipulated, the 'screw will be rotated.

A closure wall or plate 6 is secured face to face against the basemember 1 so as to cover the head 4 of the screw 3, and the wall 6 mayhave a cavity 7 upon its inner face providing clearance for the head of`the screw. The face of the base memberA 1, which is covered by the wall6, is provided with channels or grooves S and 9 along opposite sides andintersecting at one end, in which grooves resilient, conducting met-alstrips 10 and 11 may be disposed. A plug extension 12 is disposed at oneend of the base member between said member and the wall 6, and thisextension has the sleeve 13 and tip 14, as usual in telephone plugs, thestrips 10 and 11 being connected at the end adjacent the plug extensionto the sleeve and tip respectively so as to make electrrilclal 1e'.:strips 10 and 11 also assist in anchoring the plug extension 12 tothe base member.

The base member 1 and wall 6, at the end opposite the plug extension 12,may be provided with a plurality of spaced cooperating channels, eachformed partially in both abutting faces of thel member andwall, formingpassages 15 through which the metal tips of the telephone cords may be,

inserted' when establishing electrical connections between them and theinterior of j the switch. The strips- 1() and 11, at the vend adjacentthe passages 15, terminate in end adjacent the passages 15 carries adouble 45 U-shaped-cohtact element 19, with the stripextending betweenand secured to two adjacent arms of the double U-shaped member? The freearms 20 of the double U-shaped member-are disposed in approximatealignment with the two-inner passages 15, so that when the metal tips oftelephone .cords are inserted in these two inner passages, they willmake electrical contact with the free arms of the double U-shapedcontact element pand be frictionally held in the passages l5 thereby. jl A The other end of the'strip 18 is twisted through approximately 90degrees to form a leaf spring end'portion 21, and the extreme end ofthis end portion 21 is provided with a slot 22l which embraces thespindle 3 and bears upon the shoulder between the headl 4: and vtheshank of said spindle. This springl cnil 2131s preferably normallyflexed,

4so/that it constantly urges the spindle 3 in a direction to hold thebutton 5 `against the outer face'ofl the base member, thus creatingsufficient friction to hold the button in various angular positions,intowhich it may be adjusted. A pointer or indicator 23 may be secured tothe button 5, for rotation therewith in any suitable manner, such as by4a pin 24. The pointer 23 will thus indicate upon a suitable scale (notshown) provided upon the outer face of the base member 1. the variousangular adjusted positions of the button 5.

An arcuate channel or groovel 25 is provided upon the inner face of thebase meinber 1, connecting the channcls'or grooves 8 and 9. In thischannel an arcuate elcment 26 may be disposed, which elenientcxtendssubstantially-the whole length of the groove 25. The strips 10 and 11.are provided with ears 27 and 28 respectively, which extend toward oneanother and overlie the ends of the element 26 and confn( it within thegroove 25, as shown particularly in Figs. 1 and 3. The element 26 isformed preferably of insulating material, and ladjacent one end, such asthe end adjoining the ear 27, is provided on its outer face willi anotch or cut away portion 29 for a purpose to appear presently. Theouter surface or face of the. element 2G between the notch 29 and theother ear, such as 28, is provided with a conducting coating or surface:O having a high resistance, this surface or coatingextending beneaththe ear 28 so that it will always be electrically connected to thespringistrip 11. This conducting surface of high resistance does notextend across the notch 29 for reasons which will appear presently. I

A contact arm 3l is coupled to the head 4: of the spindle 3 in anysuitable manner solas to rotate with the spindle. This contactfarm ispreferably a resilient spring member, which at its outer or free endbears resilietly upon the arcuate element 26. By an angular rotation ofthe spindle 3, the contact arm 31 may be. placed over and in contactwith either car 27 or 23, or in any position upon the conducting' highresistance coating or surface 30, which is in electrical connection withthe ear lfhen this contact arm is over the notch 29, it will not be inelectrical contact with either of the ears 27 or 2S and not in contact.with the conducting surface 30. lVith this construction, it will beobserved that the double U-shaped contact element 19, which isconnectedto the vcontact arm, may, by a rotation of the button 5, be electricallyconnected selectively to either ofthe contact cars 27 and 28, or to anypoint of the resistance surface 30, or tov none ofthein when thecontact-arm 31 is i the telephone cords 34 and 35, leading to a head set36, are inserted lin two adjacent passages 15, onel of which leads tothe contact strip V11, in which position, the telephone cord tips will'bein' electrical contact'.l

with the. spring strip 11 and the contact g element 19. Let it bekassumed that the metal tips 37 arid 38 of telephone cords 39 and 404leading from a loud speaker 41, are inserted in the other twopassagesl, so' as to be in electrical '.contact-with the spring strip 11and the contact strip 19. With the parts connected in this manner, whenthe button 5 is rotated to carry the contact arm 31 into a position overthe notch 29,'the head set 36 andthe loud speaker 41 will be connectedin series with one another and to the sleeve 13 andtip '14. When theplug extension 12 is placed in jack, the sleeve 13 and tip 14 thereofwill be electrically connected to the telephone circuit' of a radio set,and since the strips 10 and 11 are connected to the sleeve and tip they'also will be connected to the telephonel circuit of the set.; Qneterminal of the head set will be connected to the strip 11 and aterminal of the loud speaker'will be connected to the other strip v10.The' other terminalsv of the headset and the loudspeaker will beconnected together' through the spring contact element 19, and togetherwill be connected to' the strip 18 and the contact arm 31. When thecontact arm 31 is over the notch 29, the head set vand loud speaker willbe connected directly 'in series with one another and in. .series with'the telephone circuit from the radio set. J

Then the button 5 is rotated to carry the contact .arm into engagementwith the ear 28 for example, the headset 36 will be short circuitedbythe contact arm 31 and will therefore be ineffective. so that all ofthe current from 'the telephone circuit in the .radio set will passdirectly through the loud speaker. When the button 5 is rotated to carrythe contact larm 31 into contact with the" ear 27` onthe other strip,th'e loud speaker will be 'short circuited rand the televao v phoneswill be connected directly across the telephone circuit, fromtheradiof'set. Thus by rotating the button' 5 into contact with eitherofthe ears 27M and 28, either the telephones or the head set'will berendered .effective and the otherfineifective.

Whenthe button 5 is rotated to carry the contact arm 31 over' theconducting surface 3-0v of high resistance, the head set will not bedirectly short circuited but will be shunted by the resistance of thecoating or surface 30 'between the ear 28 and the contact arm 31. Thisresist ance-will vary, of course,\as the contact arm moves across theconducting surface 30. Thus by rotatf` ing the button 5, the resistanceshunted across-the head set .may be varied,a"nd by reason of this shunt`more lorjless ofthe i current fromy the telephone circuit of the 'radio'set will'be v diverted directly tothe loud speaker instead ofpassingthrough the 'head set. t

-In order that the variation in resistance' .of the surface 30 may be asrapid as pos-v the rapidity of change in resistance may be n varied.This feature may also be used in connection with the tapering of thesurface if "a still varied degree of change in resistance is desired.

In Fig. 4.I haveillustrated a .modified`U construction of the element26, the modified element comprisingtwo sections 42 and 43, the section43 being of insulating material. The section 42, which is a conductingsection, tapers 'from the endconnected tothe ear 28 to the notch 29fandis'secured upon the oppositely tapered part of the insulating `section43. This modifiedv element 26 is secured in the groove 25 as intheprec'ed- .ing embodimentV and,` as the Contact arm moves over theJsection 42, theresistance w1ll vary progressively according'to thedistance of the contact ar'm from 'the ear 28 and also by reason of therapidity of change in resistance due ato the tapering'of theconduct-ingsection.

In-both` embodiments of the invention, .the element 26 is confined 'inthe grodve 25 by reason of the overlying ears 27 and 28 of the strips-10and 11,and the strips 10, 11`

- and 18 are held in their grooves by the wall 6.- The wall 6 is securedto the base mem-` ber- 1 in any suitable manner such as by screws 44which pass between them. The 'Spring end 21 of the strip 18 creates'suicient friction upon the spindle 3 to holdit in various'adjustedpositions and the friction of thejcontact arm 31 when in contact withthe `conducting surface yor with the ears. also assists in holding thebutton 1n l adi usted positions.

' When-.operating this device .iduringfthe reception of relativelystrong signals, such as from local stations/ the station may bey vtuned`in by the head set, andlinorder that the sounds emitted from the headset will not be too great. therefor or too great to be comfortable tothe `ears of the operator, the

Vbutton may be turned to carry the contact arm 31 over the conductingsurface 30 and vary the current which will be shuntedacross the headset.i In thsinanner the volume of' sound in the head set may be varied untilit in a simple manner. f' When relatively weaky signals are beingreceived, the contact arm 31 :nay be shifted to increase the proportionof current passing through the head set, so that thelatter will producethe signals with the desired volume. If at any time it is desired to cutout either the head set or the loud speaker, it may be done by rotationof the contact arm into engagement with the ears 2S or 27 respectively.

If it is desired to operate-both head set and loud speaker in serieswith one another, t is merely necessary to shift the contact arm 31 intothe notch 29,'in which position it will not have electrical contact witheitherv strip 10 and 11 and the head set and loud speaker will bevdirectly in series' with one another. If the' conducting surface 30becomesworn, brokenl or deteriorates, a new element 26 with a newconducting surface oi coating may be readily inserted in the groove 25,since ali the parts are held in their -grooves by the wall 6. The endsof the notch 29 are preferably beveled so that the Contact arm willAreadily ride up either end-of thel same as it is being shifted in eitherdirection.- A

While the invention has been described in connection with a` lug forconnecting various types of telep one receivers to a telephone circuit,it will be understood that this is illustrative only and that theinvention has many applications to other electrical arts. It will alsobe obvious that various changes in the details and arrange ents ofparts,

'which have been herein describedl and illustrated for the purpose ofexplaining the nature of the invention, may be made. by those skilled inthe art within the principle .and scope of the invention as expressed inthe appended claims.

1 claim:

l. A telephone switch forradio sets, comprising a pair ofconductors forconnection in the telephone circuit of a set, a support for theconductors, a switch member carried -by the support for; movement in adefinite path "thereon, spaced contact elements, one connected to eachofthe two conductors and another to the switch member, whereby atelephone receiver ma .be electrically connected bctweenonefo theconductors and the velement l thatis' connected to the switch member,and another receiver between the other of the said conductors and theswitch member, and switch elements connected to the two conductors anddisposed in spaced relation to one another within the path of the'switchmember, whereby either receiver may be temporarily short circuited bymoving the switch member into engagement with that switch element whichis connected to the same conductor that that receiver is directlyconnected to, and both receivers rendered active and placed in seriesbyqnoving the switch member out of engagement with both switch elements.

2. A telephone switch for radio sets, comprising a'pair of conductorsfor connection in-the telephonecircuitof a set, a support for theconductors, a switch member carried bythe support for movement in adeiinite path thereon, spaced contact elements, one connected to each ofthe two conductors and another to the switch member, whereby a telephonereceiver may be electrically connected between one of the conductorsandl the element that is connected to the switch member, and anotherreceiver between the other of the said conductors and theA switchmember, switch elements connected to the two conductors and disposed inspaced relation to one another within the pathof the switch member,ywhereby either receiver may be temporarily short circuited by moving theswitch member into engagement with that switch element which isconnectedto the as ,I

same conductor that that receiver is directly I connected to, and bothreceivers rendered active and placed in series by moving the switchmember out of engagement with both switch elements, and a. resistanceelement` within the path of the switch member and electrically connectedto-one of the switch elements whereby as the switch member moves overthe resistance element a vari-` able resistancc will be connected acrossone of the receivers while they are in series whereby the relativecurrents through said receivers may-be balanced .or given variousdesired relative values.

3. The telephone switch for -radio sets,

substantially as set forth in claim 2, in f which the resistance -of theresistance element variesthroughout its length.

4. The telephone switch for radio sets,

.substantially as set forth in claim 1 in which -the support carries ajack plug tothe tip and sleeve of which' the conductors a-re connectedrespectively.

5. The telephone switch for radio sets, `substantially as set' forth inclaim -1 in which the spaced contact elements have clips for detachablyclamping the usual telephone cord tips of receivers. I 'I 6. The1telephone` switch for radio sets, substantially as set forth in claim 1,in which the support carries ajack plug to the tip and' sleeve ofwhichthe conductors are iso said common circuit are connected, said aux'1l1ary clrcuits being connected 1n series and' to said contacts, .meansincluding a contact 'arm connected to the series connection between theauxiliary circuits and movable selectively into engagementV with eitherof the spaced contacts for selectively shunting.

e either o f the auxiliary circuits.

- 8. A switch for connecting a plurality of auxiliary circuits to acommon circuit in various relations comprising a pair of spacedcontacts, to which the conductors of said common circuit are connected,said auxiliary circuits being connected in series and* to said contacts,means including a contact arm connected to the serls connection betweenthe auxiliary circuitsv and movable selectively into engagement witheither of the spaced contacts for selectively shunting either ofthe-auxiliary circuits, and a re-A sistance element disposed in the pathof the ycontact arm and connectedto one of said spaced contacts so' thatthe resistance of the shunt across one of` the auxiliary circuits may beselectively varied.

9. A switch for connecting a plurality of auxiliary circuits to a commoncircuit vin various relations com rising a pair vof spaced contacts to`whic the .conductors of said common circuit are'connected, said auxdiliary cilcuits being connected in series and to said contacts, meansincluding a contact arm connected tothe serles connection bespaced.contacts for selectively shunting either of the auxiliary circuits',and means including a contact arm connected to the series connectionbetween the auxiliary cirtween the auxiliarycircuits and movableselectively into engagement with either of the cuits and movable in apath in4 which' itY will engage said spaced contacts successively so vasto shunt either of the auxiliary circuits, andX a resistance elementdisposed "between said spaced contacts within` the path. ,of said armand electrically -connected to one of said spaced contacts whereby therelsistance of the shunt across vone of said 10. A switch for connectinga plurality of' auxiliary circuits to )a common circuit` 1n variousrelations comprising a pair of .spaced contacts to which the conductorsof said common circuit are connected, the auxiliary circuits beingconnected in series with one another 'and to said contacts and anoninductive variable resistance device `interposed between one of saidcontacts Aand/the series connection between the auxiliary circuitswhereby one'of said auxiliary circuits may be shunted by a variablenon-inductive resistance, said lresistance devicebeing movable intoka4condition in which the shunt is ineffective and also into a conditionwhich directly shunts the other of said auxiliary circuits.

In witness whereof, I hereunto subscribe my signature.

EDWARD ANTHONY SMALENBERGER.

